Data centers house business-critical applications and information on servers that run 24 hours a day, generating extreme amounts of heat. Reliable, efficient HVAC systems are crucial to cool storage servers and eliminate the risk of damage caused by overheating. To ensure healthy operation of HVAC systems, regular system maintenance is essential.

HVAC systems maintain temperatures inside data centers by circulating cooling water or air. The coolant flows through chiller tubes, which often have spiral grooves inside of them. These inner grooves help ensure efficient heat transfer, but corrosion, pitting, and deposition tend to occur around the spiral lines. While straight chiller tubes are often inspected using eddy current (ECT) and ultrasonic testing (UT), the integrity of the inner grooving of the tubes is difficult to validate with those methods. Further complicating the inspection, many chiller tubes have a U-shape in the middle. The bottom curve of the U-shape is a vulnerable point subjected to the load of circulated fluids during system operation. Remote visual inspection (RVI) using a videoscope is the recommended method to inspect both the inner groove and the conditions of the U-shape.

Selecting the optimal videoscope

To conduct quality inspections of data center facilities, it's crucial to select an optimal videoscope with the required features. Here are some tips on what is needed to conduct a proper HVAC tube inspection.

1. Determine insertion tube length requirements.

Make sure the videoscope has an insertion tube long enough to inspect the targeted sections of the HVAC or chiller system. Insertion tube lengths can vary from 2 meters (6.5 feet) to 30 meters (98 feet), and the proper selection depends on the length of the pipes and tubes to be inspected. Chiller tubes typically require a videoscope with a long insertion tube of around 7.5 to 10 meters (25 to 33 feet) in length. Note that it’s usually more cost-effective to choose a videoscope with interchangeable insertion tubes for added inspection flexibility.

2. Use a videoscope that provides bright, clear images

Bright, clear imaging is another important aspect of data center HVAC inspections. When looking for damage inside narrow HVAC tubes, you need the optimal amount of brightness. If the image is too bright, a high amount of reflection can occur, leading to unclear images. In contrast, too little brightness will yield dark images and a higher probability that you could miss seeing a defect. Make sure that you choose a videoscope featuring advanced brightness adjustments in order to obtain high-quality images and, consequently, a higher probability of detection.

3. Select optical tip adapters to optimize your view

For the inspection of various types of tubes and pipes, selecting suitable optical tip adapters is another important aspect of the videoscope technique. When you want to conduct screening inside a tube to thoroughly check for potential defects, a far-focus adapter will work well. When you want to scrutinize the conditions of defects, a near-focus adapter with side viewing is recommended.

4. Use an optimized insertion tube to easily access hard-to-reach spaces

A well-designed insertion tube can ease videoscope inspections of hard-to-access or deeper targets within HVAC or chiller systems. Generally, inserting a long videoscope into a pipe or tube is more difficult than using a short one. In long tubes, such as HVAC chiller tubes, the pushing force applied by the operator weakens the further the scope tip advances, and the weight of the insertion tube, scope tip, and friction against the inner surface cause resistance. Therefore, it's important to use a videoscope with well-balanced stiffness and flexibility from the scope root to the tip. These characteristics can help you achieve a smooth scope insertion and precise scope bending. Additionally, when inspecting extra-long pipes and tubes with bending sections, make sure to exploit dedicated accessories that assist scope insertion, such as a pushing rod adapter and guide head.

Conclusion

Because of the important nature of the digital infrastructures they support, data center operators have a responsibility to maintain their facilities and keep their servers running smoothly. Remote visual inspections support the stable operation of data center HVAC systems, and the right videoscope can be a critical component of an efficient maintenance program for these facilities.